Boutros Boutros-Ghali expressed ''disappointment and surprise'' at Mr Karadzic's refusal to discuss the UN's ''simple message'' - to negotiate in good faith and co-operate with the peace-keeping mission, or face a UN withdrawal.
Putting a brave face on what was a disastrous day for the UN, Mr Boutros-Ghali, who was booed by a crowd of angry Sarajevans, said he remained ''an optimist''. ''We must continue to negotiate, we must continue to encourage dialogue,'' he said. Such a task will be difficult if Mr Karadzic, whose forces are holding around 450 peace-keepers virtual hostages, refuses to talk.
Mr Karadzic insisted Mr Boutros-Ghali come to Serb-held territory. Mr Boutros-Ghali refused because the UN does not recognise the self-declared Bosnian Serb statelet.
Bosnia's President, Alija Izetbegovic, earlier assured Mr Boutros-Ghali his government accepted both conditions for the continuation of the UN mission, but angrily demanded that the UN side with his government. The Secretary-General, he said, ''should use [his] authority to say very clearly that here in Bosnia-Herzegovina, as he knows from all the facts, there is a conflict between a democratic and legal government . . . and a black fascism. He must say clearly to the French, British and other powers . . . that the legal government must be defended.''
''I cannot get heavy with anybody,'' Mr Boutros-Ghali said, rejecting charges of UN failure around Bihac. And despite omitting even to ask the Serbs to guarantee the minimum conditions for the UN presence, he said: ''I will not recommend for the time being the withdrawal of Unprofor.''
As one official said, the UN may continue to ''shrink from its mission and carry on''. If troop-contributing nations pull out, it will have avoided taking responsibility for the decision. But the UN has proved itself unable to keep Bihac ''safe'', and the consequences might extend far beyond the pocket. The Croatian Defence Minister, Gojko Susak, said that if the enclave falls, Zagreb will rejoin the war. ''If it came to a situation where Bihac would fall for whatever reason . . . Croatia would intervene,'' he told the New York Times.
Washington has already dissuaded Zagreb once from entering the Bihac fight and last night a State Department spokeswoman, Christine Shelly, urged Croatia not to enter the war against the Serbs.
Mr Susak and his government may succumb again to such pressure. But his words imply that Mr Boutros-Ghali's failure to persuade the Serbs to agree to a ceasefire around Bihac, and the peace-keepers' inability to protect the area, could restart the Croatian war. This would bring a complete collapse of international policy, which has been aimed primarily at containing the war within Bosnia.
Mr Boutros-Ghali did not explain why the Serbs, who have repeatedly rejected the five-nation Contact Group peace plan - which he said was still the only basis for a settlement in Bosnia - should change their minds now, when the threat of Nato air power appeared to have evaporated. ''I think they have the taste of blood in their mouths now,'' said one analyst.